Fuel pressure sensor for safety

[kalns]

Hello to every one.
I have vems v3.6 unit, running opel c20let turbo with a lot of custom parts, and i want to add a little more safey features to protect it.

I have installed 12mpa fuel pressure sensor and wired acordingly. I understand how to use calibration wizard to set it up.
0.5v-4.5v 0-12mpa slope
The thing that I do not understand is how to implement ignition cut if fuel pressure drops lets say below 3bar. Or do any other safety related thing to protect engine from damage.
If this works, I would like to do thesame for oil pressure.
Or i can only log this kind of inputs ?

[GintsK]

Look at anytrim functions under Motorport. Among other functions you also can trim rev limiter from various inputs.

[kalns]

So i have to chose Anytrim3 Soft-Cut Rpm Trim(add) function, and advance ignition if fuel pressure is lower than 3bar. Do I understand correctly how to use this function?

[GintsK]

once you setup input and affected function, you get editable graph with live tracing of actual value. Usually self explanatory.

any kind of redline trimming from FP will cause engine jerking. I would suggest to try some fuel trim from FP or lambda deviation (also under anytrim), but control engine safety measures using warning lamp from 1) FP analogue channel 2) from lean condition under high power or both. You can also use warning lamp output for switching safety config (look at config switch).
 
P.S. usually you want retard, not advance, ignition under dangerous conditions.

[kalns]

I will wire up warning lap also, and I was thinking about table switching to limp mode table but for that I will need a lot more help later to understand what should be done, to set it up correctly. To set up warning lap to switch tables, its output should be routed back to table switching pin and if nececery use inverted state ?

Could you explain more about fuel trim idea ? If fuel pump is dying and fuel pressure is dropping, then add X % of fuel. Is this correct ?

[GintsK]

If you wnat switch configs from warning lamp, yes just wired solution. I do not think it is optimal way because you do not even notice warning light by eye...

Regarding fuel trim there is just workarounds until you have no differential pressure signal - actual value from what you want corrections. VEMS sell such sensor. Or it can be "calculated" by using free onboard opamp.

[kalns]

I have noticed this sensor on webshop, I dont get how this is diffrent from what i want to achieve with the sensor i have. Does vems cannot calculate differential pressure between two sensors, ie map and fuel pressure sensor ?

So if I would install this dufferential pressure sensor, I would not have to have onboard map sensor, is that right ? Or is it making some kind of compensation since there would be boost pressure to account for ?

Anyway, can you give some more info about onboard opamp, so I can educate myself a bit ? I will take a look into this approach, maybe its mutch easier to install this sensor and get what i want..